<template>
    <div class="login_container">
        <div class="login_box">
           <div class="avatar_box">
               <img src="../assets/logo.png" alt="">
           </div>
            <!-- 登录表单区 -->
           <el-form ref="loginFormRef" label-width="80px" class="login_form" :model="loginForm" :rules="loginFormRules">
               <!-- 用户名 -->
               <el-form-item prop="username">
                   <el-input prefix-icon="iconfont icon-user" v-model="loginForm.username"></el-input>
               </el-form-item>
               <!-- 密码 -->
               <el-form-item prop="password">
                    <el-input type="password" prefix-icon="iconfont icon-3702mima" v-model="loginForm.password"></el-input>
               </el-form-item>
               <!-- 按钮区域 -->
               <el-form-item class="btns">
                    <el-button type="primary" @click="login">登录</el-button>
                    <el-button type="info" @click="resetLoginForm">重置</el-button>
               </el-form-item>
           </el-form>
        </div>
    </div>
</template>
<script>
export default {
    data(){
        return {
            // 这是登录表单的数据绑定对象
            loginForm: {
                username: "",
                password: ""
            },
            loginFormRules:{
                // 验证用户名是否合法
              username: [
                { required: true, message: '请输入用户名', trigger: 'blur' }, //required表示是必填项，
                { min: 3, max: 10, message: '长度在 3 到 10 个字符', trigger: 'blur' }  //message表示错误时的提示文字
              ],
              password: [
                { required: true, message: '请输入登录密码', trigger: 'blur' },
                { min: 6, max: 15, message: '长度在 6 到 15 个字符', trigger: 'blur' }
              ]
            }
        }
    },
    methods: {
        resetLoginForm(){
            this.$refs.loginFormRef.resetFields();
        },
        //登录前预验证，若表单符合验证规则，返回一个true,否则返回false
        login(){  
            this.$refs.loginFormRef.validate(async valid => {
               if(!valid) return;
               const {data : res} = await this.$http.post("login",this.loginForm);   //这里的login是请求地址url,loginForm是data里的数据,通过解构结果里的data属性，使用await和async可以进行优化
               if(res.meta.status !== 200) {return this.$message.error('登录失败！')}
               else {this.$message.success('登录成功！')}
               window.sessionStorage.setItem("token",res.data.token);  //将登录成功之后的token保存到客户端的sessionStorage中，这样在登录成功才能访问其他API接口
               this.$router.push("./home"); //点击登录就会跳转到home页面
            }) 
        }
    }
}
</script>
<style lang="less" scoped>
  .login_container{
      height: 100%;
      background-color: #2b4b6b;
  }
  .login_box {
      position: absolute;
      top: 50%;
      left: 50%;
      transform: translate(-50%,-50%);
      width: 450px;
      height: 300px;
      background-color: #fff;
      border-radius: 3px;
  }
  .avatar_box {
      position: absolute;
      top: 0;
      left: 50%;
      transform: translate(-50%,-50%);
      width: 130px;
      height: 130px;
      padding: 10px;
      border: 1px solid rgb(216, 208, 208);
      border-radius: 50%;
      background-color: rgb(216, 208, 208);
      box-shadow: 0 0 5px #eee;
      img {
          width: 100%;
          height: 100%;
          border-radius: 50%;
      }
  }
  .login_form {
      position: absolute;
      bottom: 0;
      left: -40px;
      width: 100%;
      box-sizing: border-box;
  }
  .btns {
      display: flex;
      justify-content: center;
  }
</style>
